The agent with a secret past

She forged her way to citizenship, joined the FBI and CIA, and then accessed computers for restricted information.

WASHINGTON — An illegal immigrant from Lebanon with relatives linked to the militant Islamic group Hezbollah paid a U.S. citizen to marry her and then lied her way through national security background checks to become an agent for the FBI and the CIA. She used her position to secretly access government computers for information about her relatives and a U.S. investigation into the group, authorities said Tuesday.

Nada Nadim Prouty, a 37-year-old Lebanese national, pleaded guilty to conspiracy, unauthorized computer access and naturalization fraud in federal court in Detroit and agreed to cooperate with authorities in an ongoing investigation into the security breaches.

Prouty's case is a major embarrassment for the FBI and the CIA, which supposedly had tightened their personnel screening and monitoring after CIA officer Aldrich H. Ames and FBI Special Agent Robert Hanssen were caught selling secrets to foreign governments. But officials emphasized that the investigation had not uncovered any evidence that Prouty gave Hezbollah or its operatives classified information.

Law enforcement officials said a multi-agency probe was underway to determine how the breaches occurred, what Prouty may have done with the information she accessed from FBI computers, and whether she improperly obtained information from the CIA.

"It is hard to imagine a greater threat than the situation where a foreign national uses fraud to attain citizenship and then, based on that fraud, insinuates herself into a sensitive position in the U.S. government," U.S. Atty. Stephen J. Murphy in Detroit said in a statement.

In her signed plea agreement, Prouty admitted to accessing FBI computer files on Hezbollah first in 2000 and again in 2003, when she accessed case files on a top-secret national security investigation into the militant group that the FBI was conducting.

At the time, Prouty's brother-in-law, who owned a Detroit restaurant where Prouty once worked as a waitress, was suspected of having strong ties to senior Hezbollah officials in Lebanon, where the group is headquartered.

Prouty also was accused of improperly taking classified information home while at the FBI, and of working with other Lebanese nationals in what appeared to be a conspiracy to gain U.S. citizenship through fraudulent marriages and then get government law enforcement, intelligence and military jobs with security clearances.

The ongoing investigation is being conducted by the FBI and the Department of Homeland Security's Immigration and Customs Enforcement bureau, with assistance from the State Department's Diplomatic Security Service and the Internal Revenue Service, officials said. Immigration and Customs Enforcement spokeswoman Kelly Nantel said it was too early to say what kind of security breaches might have been involved.

Prouty faces a maximum penalty of 16 years in prison and $600,000 in fines, and loss of her U.S. citizenship. But under the terms of the plea deal, she faces only six to 12 months if she cooperates fully.

"I'm not sure this speaks tremendously well of either agency," one U.S. official who is familiar with the case said of the FBI and the CIA.

"But the fact of the matter is that this is a case of naturalization fraud. At this point, there is no reason to treat this as a counter-intelligence case," said the official, who spoke on the condition of anonymity because he was not authorized to speak publicly about the case.

Officials would not say how Prouty's scheme was exposed. Willie T. Hulon, executive assistant director of the FBI's National Security Branch, said the bureau became aware of Prouty's activities in December 2005 and moved to address any further damage. "We continue to evaluate our security practices and will make any necessary changes," Hulon said in a statement.

CIA spokesman Paul Gimigliano said the agency was cooperating with the investigation. "The naturalization issue occurred well before she was hired by the bureau" and 13 years before she joined the CIA, he said.

Attempts to reach Prouty's lawyer Thomas W. Cranmer were unsuccessful. A relative of Prouty, reached by phone from California, said Tuesday night that she could not discuss the case or anything about the former CIA officer.

To join the FBI and CIA, Prouty had to be a U.S. citizen and undergo a background check. Officials at both agencies insisted that thorough background checks had been done. FBI spokesman Stephen Kodak said agents interviewed family, friends and associates in the U.S. and Lebanon to make sure Prouty did not pose a security risk, and that Prouty passed a polygraph test.

"We relied on her legitimate naturalization documents. What the investigation revealed was that those naturalization papers were obtained through a long-term pattern of fraudulent claims," Kodak said. "Do additional measures need to be implemented? Possibly."